Some pharmacologically active substances may have biopharmaceutical and/or physicochemical properties which make them difficult to formulate into common administration forms. Such substances may be conveniently administered in liquid form either in a lipophilic or hydrophilic carrier system, either as a solution or a suspension, either mixed with a single carrier excipient or mixed with a complex carrier medium made up of several components. Encapsulation of such liquid formulations in soft gelatin capsules potentially offers a very convenient way of administering such pharmacologically active substances.
Solutions
To formulate a solution based system the carrier has to dissolve the active substance. Improved gastrointestinal (GI) absorption of poorly absorbable drugs can be achieved by increasing the dissolution rate of the drug in the presence of bile acids. Within the gastrointestinal tract, bile salts behave as biological detergents that, when mixed with phospholipids, form thermodynamically stable mixed micelles. In many instances the choice of formulation will be limited by solvent capacity, and in others the drug will not be sufficiently soluble in any lipid formulations.
The carrier medium may be designed to spontaneously form an emulsion or microemulsion in the stomach thereby facilitating absorption of the pharmacologically active substance. These systems are commonly known as self (micro-)emulsifying drug delivery systems (SEDDS or SMEDDS). They have to be accurately prepared and even slight variations in the composition cannot be tolerated without irreversibly upsetting the system, and destroying its beneficial properties. For example, the active substance may precipitate out as a consequence of a change in the solubilizing properties of the capsule formulation. This precipitation process may be irreversible and lead to an under-dosing of the patient. The emulsifying properties of the capsule formulation may also be changed, and, upon administration, an emulsion may not be formed in the stomach. As a consequence, the pharmacologically active substance may not be correctly or reproducibly absorbed.
Suspensions
As suspensions do represent thermodynamic instable multiphase systems, various characteristics have to be taken into account during development of these systems. The physical stability of the suspension formulation has to be ensured from the perspective of particle growth as well as from the perspective of re-crystallization in a potential polymorphic form which may have a different solubility or from the perspective of sedimentation associated by caking of the sediment. These factors may influence the liberation of the active substance from the dosage form and hence alter the extent of patient's exposure during the shelf-life of the product. Hence no solubility of the active substance in a single carrier excipient or in the carrier system would be the prerequisite for a physically stable system.
Lipophilic Carrier Systems
Lipophilic excipients are commonly employed as moisture barrier systems to protect chemically instable substances. For this purpose, different types of fats or waxes may be applied on solid dosage forms or on their manufacturing intermediates to prevent migration of ambient water vapour or oxygen and to improve the chemical stability of the active substance. Hot-melt inclusions of the drug into lipophilic binders may as well prevent contact with moisture. Since solid hydrophobic systems poorly disintegrate, drug release in these systems is delayed, in contrast to drug release in low viscous liquid lipid formulations. This delayed drug release is reflected by the specific plasma profiles of the active substance of a modified drug delivery system (Ritschel W. et al., Die Tablette, 2002, 2nd ed., ECV, Aulendorf, p. 2671). Hence, viscosity of liquid systems is a crucial parameter and has to be carefully adjusted to ensure adequate drug release.
In practice lipophilic or ‘lipid’ formulations are a diverse group of formulations which have a wide range of properties. These result from the blending of up to five classes of excipients, ranging from pure triglyceride oils, through mixed glycerides, lipophilic surfactants, hydrophilic surfactants and water-soluble cosolvents.
Assessment of Quality
The performance of a formulation may be assessed by measuring its relative bioavailability, i.e. comparing its bioavailability with the bioavailability of an aqueous solution of the active substance. If the systems show a comparable bioavailability, not with respect to the dissolution rate but with respect to the drug permeability, pre-systemic or systemic metabolization of the active substance will determine the systemic exposure. Thus, (lipid) suspensions may also show satisfactory exposure of the patient due to the adequate solubility of the active substance within physiological conditions.
3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone-monoethanesulphonate is an innovative substance having valuable pharmacological properties, especially for the treatment of oncological diseases, immunologic diseases or pathological conditions involving an immunologic component, or fibrotic diseases.
The chemical structure of this substance is depicted below as Formula (I).

This substance is described as base in WO 01/27081, as monoethanesulfonate salt form in WO 2004/013099, for its use in the treatment of immunologic diseases or pathological conditions involving an immunologic component in WO 2004/017948, for its use in the treatment of oncological diseases in WO 2004/096224, for its use in the treatment of fibrotic diseases in WO 2006/067165, and as other salt forms in WO 2007/141283.
The aim of the present invention is to obtain for the above drug substance an oral pharmaceutical dosage form which meets adequate chemical stability as well as bioavailability requirements for the desired dosage range tailored to treatment, and a packaging material suitable for the product. Such specific pharmaceutical dosage form is not known from the prior art for this drug substance.